package com.atguigu.java;

import org.junit.Test;

public class IDEADebug {
    @Test
    public void testStringBuffer(){
        String str=null;
        StringBuffer sb = new StringBuffer();
        sb.append(str);
        System.out.println(sb.length());
        System.out.println(sb);
        StringBuffer sb1 = new StringBuffer(str);
        System.out.println(sb1);
    }
}
